In this paper, we introduce a structural model for WDM(Wavelength Division Multiplexing)based LT(Line Termination) systems containing the fundamental functions recommended by ITU-T, and we describe how to configure th...
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ISBN:
(纸本)0819426636
In this paper, we introduce a structural model for WDM(Wavelength Division Multiplexing)based LT(Line Termination) systems containing the fundamental functions recommended by ITU-T, and we describe how to configure the supervisory system and data communication channels to be adaptable to the WDM-based transmission systems considering compatibility with the SDH-based supervisory systems. Also we propose that two new reference points(N2 and N3) be added to the MCF(Message communication Function) like N and P from the view point of the telecommunication management network.
Currently, the developed bi-directional broadband Passive opticalnetworks (PONs) have a maximum splitting factor around 32 and a range less than 20km. Due to the expected switching node consolidation the access netwo...
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Architectural and algorithmic principles of the common planar multistage interconnection network are reviewed. For the purpose of its proper operation in the circuit switching mode the enlarged planar network and the ...
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ISBN:
(纸本)0819423211
Architectural and algorithmic principles of the common planar multistage interconnection network are reviewed. For the purpose of its proper operation in the circuit switching mode the enlarged planar network and the multiple planar network are introduced. Additionally, a novel planar 4 X 4-switch is presented and applied to two planar architectures with switches of size >= 4 X 4.
In this paper, we study an adaptive algorithm for routing in an all-optical wavelength routed network where a lightpath is dynamically created in response to a request for communication and the WDM channels constituti...
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ISBN:
(纸本)0819426636
In this paper, we study an adaptive algorithm for routing in an all-optical wavelength routed network where a lightpath is dynamically created in response to a request for communication and the WDM channels constituting the lightpath are reclaimed when the communication is over. We have proposed three possible distributed strategies to determine, if possible, a lightpath when there is a request for communication. Each of these strategies have their advantages and disadvantages in terms of the expected blocking probability and the set-up time. We consider the Kautz digraph as the network topology and study the performance of our distributed strategies through simulation.
Fractional-N cascaded PLLs, which utilize a 1 st -stage integer loop as the reference frequency multiplier and a 2 nd -stage fractional loop as frequency synthesizer, serve as the building block in modern wireless sys...
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ISBN:
(数字)9798331517458
ISBN:
(纸本)9798331517465
Fractional-N cascaded PLLs, which utilize a 1 st -stage integer loop as the reference frequency multiplier and a 2 nd -stage fractional loop as frequency synthesizer, serve as the building block in modern wireless systems [1]–[8]. Benefitting from small layout area and easy integration, the ring oscillator (RO)-based reference frequency multiplier is widely used as the 1 st -stage PLL [9], yet it invariably suffers from inferior noise and limited spur control due to their high K RO-VCO and susceptibility to power supply variations [10]. In this context, various approaches, including sampling PLLs, delay-locked loops, and injection-locked clock multipliers, have been explored to extend the closed-loop bandwidth of the 1 st -stage as well as to suppress the internal RO noise [9]–[17]. Nonetheless, the reported bandwidths are limited below fREF/2 due to the PLL stability issues, leaving the PLL phase noise (PN) impaired by the residual RO noise. Alternatively, a feed-forward noise cancellation technique has been proposed to cancel the RO noise, but it requires background calibration to adjust the feed-forward gain [18]. In this paper, we propose a cascaded PLL architecture that incorporates a calibration-free over-sampling cancellation path to cancel the noise and spurs generated in the 1 st -stage RO-based PLL across all frequencies. Meanwhile, we also introduce a 4th-order LC ladder-based LC-OSC in the 2 nd -stage that suppresses the 4th harmonic noise, achieving a FoM of 192 dBc/Hz at 10 MHz offset. Accordingly, when it is clocked by a 100 MHz reference signal, the proposed cascaded PLL achieves a 127.8 fs rms jitter and an equivalent 1 st -stage bandwidth $(f_{\text{eq}-\text{bw}1})$ exceeding $3f_{\text{REF}}$ with only a 4.48 mW power consumption, and its overall FoM reaches −251.4 dB.
all-opticalcommunications based on OFDM techniques are very attractive for future telecommunications. However, the frequency instability of semiconductor laser diodes still constitutes an obstacle to exploit OFDM ben...
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ISBN:
(纸本)0819426636
all-opticalcommunications based on OFDM techniques are very attractive for future telecommunications. However, the frequency instability of semiconductor laser diodes still constitutes an obstacle to exploit OFDM benefits. In this paper, we present a decentralized frequency control system suitable for large scale all-opticalnetworks. Spectrum partitioning is proposed so that the controllable spectral range could be enlarged and link fault could be detected. Experimental results on monitoring and stabilizing a channel frequency in a local node, confirm the feasibility of the described method.
The deployment of an allopticalnetwork requires that all transmission and switching equipment be properly synchronized. The synchronization performance characterization of telecommunication equipment and networks re...
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ISBN:
(纸本)0819426636
The deployment of an allopticalnetwork requires that all transmission and switching equipment be properly synchronized. The synchronization performance characterization of telecommunication equipment and networks requires a wide variety of specialized equipment, each one performing a specific task, with limited data collection, transfer, and analysis capabilities. Most of the required equipment is heavy, difficult to use, and occupy substantial floor space. A portable, user friendly, and easy to maintain automatic test station for synchronization performance monitoring and characterization has been developed.
A new layered structure for multi-wavelength photonic transport networks is proposed after optical wavelength-division-multiplexing(WDM) technologies and optical path technologies are introduced. Photonic layer is ins...
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ISBN:
(纸本)0819426636
A new layered structure for multi-wavelength photonic transport networks is proposed after optical wavelength-division-multiplexing(WDM) technologies and optical path technologies are introduced. Photonic layer is inserted between traditional physical layer and section layer. It can be divided further into three sublayers: optical path layer, WDM section layer, and multi-wavelength amplifying section layer. The functions of photonic layer and its sublayer are defined. Some problems that are related to photonic layer are discussed and solved. network management issues are also discussed in this paper.
This paper shows the state of the art in fiber optical code-division multiple-access (CDMA). Recent work in this area for both, systems and sequences is reviewed and analyzed. For that purpose a classification of syst...
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ISBN:
(纸本)0819419788
This paper shows the state of the art in fiber optical code-division multiple-access (CDMA). Recent work in this area for both, systems and sequences is reviewed and analyzed. For that purpose a classification of systems, corresponding to the manner of signal processing and a classification of known (0,1)-sequences are presented. It is shown that due to the limits by currently available device technology especially two techniques are promising for implementation in broadband telecommunicationnetworks: spectral encoding with integrated optical filters and CDMA in combination with wavelength multiple access schemes. Further an overview about some important experiments in this field is given.
An architecture of an all-optical multistage interconnection network is proposed. The network supports a circuit-switching model of communication and can provide parallel optical paths among input and output ports. It...
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An architecture of an all-optical multistage interconnection network is proposed. The network supports a circuit-switching model of communication and can provide parallel optical paths among input and output ports. It uses an address-based routing algorithm for path setup which, due to its decentralized nature, makes this network suitable for designing high-speed switching systems. These switches are commonly used in telephony and multiprocessor systems. The proposed architecture uses bistable optical devices, such as interference filters, as essential components of its switching modules. Since these devices can be easily fabricated, the implementation of this architecture is feasible. Various design issues related to optical clock generation, its distribution, data synchronization, and intensity restoration are also discussed.
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